#include <fstream>

using namespace std;
int gcd(int a, int b) {
    return b == 0 ? a : gcd(b, a % b);
}
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int main()
{
    int n,cnt,i,j;
    fin>>n;
    cnt=0;
    for(i=1;i<=n;i++)
    {
        for(j=i;j<=n;j++)
            if(gcd(i,j)==1)
            cnt=cnt+2;
    }
    fout<<cnt-1;
    return 0;
}